Dieletric
Mostrando 1-12 de 18 artigos, teses e dissertações.
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1. C-Band Monopulse Planar Array and Feeding Network
Abstract Monopulse radars operate with simultaneous beams and are used for tracking purposes, relying only on hardware to provide a real-time indication of the target position. A monopulse array and its feeding network is implemented and tested, in the frequency of 5.4 GHz, based on patch antennas using dieletric to provide wide bandwidth and high gain. The
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2021-06
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2. Extremely high Faraday and Kerr rotations and extraordinary optical transmission in four-layer dielectric-metal strips-dielectric-Bi:YIG planar structure
Abstract Faraday and Kerr effects as well as the extraordinary optical transmission in a structure that combines magneto-optical and plasmonic properties are studied. The planar structure consists of four layers, namely, dielectric layer, metal strips, once again dieletric layer and magneto-optic one. The magneto-optical layer is magnetized by a DC magnetic
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2018-03
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3. Estudos das propriedades dielétricas em micro-ondas de cerâmicas dos sistema ZnO-Nb2O5-TiO2 para aplicações em comunicações espaciais / A study of microwave dielectric properties of ZnO-Nb2O5-TiO2 ceramic system for applications in space communicatios
O crescente desenvolvimento das telecomunicações impulsiona a pesquisa por novas tecnologias que possibilitam o aprimoramento do desempenho dos equipamentos. Cerâmicas dielétricas encontram aplicação como ressoadores dielétricos (RDs) em sistemas de comunicação que operam em frequências de microondas. Para a construção de um ressoador dielétrico
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 29/08/2011
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4. Excitação de ondas de helicon e de Alfvén em tokamak TCABR / Excitation of Helicon and Alfvén waves in tokamak TCABR
The objective of this work is to investigate the excitation of waves in a plasma using an antenna and to analyse the Alfvén resonances found. The Alfvén antenna heating system of the TCABR tokamak was designed to heat the plasma due to resonances. As the diodes of the toroidal field had burned down we used cleaning discharges, with low toroidal magnetic fi
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 04/04/2011
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5. Reducao da influencia da massa especifica na determinacao do teor de umidade de sementes de trigo.
A medicao da capacitancia e da condutancia de um capacitor contendo amostras de trigo permite a determinacao de duas de suas propriedades dieletricas: a permissividade relativa (E') e o fator de perda dieletrica (E"). A utilizacao dessas propriedades, medidas simultaneamente em duas frequencias de oscilacao do campo eletrico, permite reduzir ou eliminar o ef
Pesquisa Agropecuaria Brasileira. Publicado em: 2011
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6. Estudo de transistores SOI de múltiplas portas com óxidos de porta de alta constante dielétrica e eletrodo de porta metálico. / Study of SOI multiple gate transistors with gate oxide of high dieletric constant and metal gate electrode.
Este trabalho tem como objetivo investigar o comportamento de transistores SOI de porta tripla com óxido de porta de alta constante dielétrica e eletrodo de porta de metal. Inicialmente estudou-se a aplicação dos métodos de extração de parâmetros através de curvas da capacitância, previamente desenvolvidos para estruturas SOI planares, em dispositi
Publicado em: 2010
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7. Propriedades física de molécilas orgânicas e compostos do tipo perovskita CdSiO3 e CaPbO3
In the first part of this work our concern was to investigate the thermal effects in organic crystals using the theory of the polarons. To analyse such effect, we used the Fröhlichs Hamiltonian, that describes the dynamics of the polarons, using a treatment based on the quantum mechanics, to elucidate the electron-phonon interaction. Many are the forms to a
Publicado em: 2009
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8. Synthesis and dielectric properties of the lase sintered Ba1-xCaxTiO3 (0 ≤ x ≤ 0.30) nanostructured ceramics / Síntese e propriedades dielétricas de cerâmicas nanoestruturadas de Ba1xCaxTiO3 (0 menor igual x menor igual 0.30) sinterizadas a laser
Ba1-xCaxTiO3 (0 ≤ x ≤ 0.30) nanocrystalline powders were successfully synthesized for the first time at relative low temperature (500 °C) by a modified polymeric precursor method. The densification of the ceramics was made by two distinct techniques: conventional sintering using an electric furnace; and by a laser sintering process in which a CO
Publicado em: 2006
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9. Sensor de umidade microeletronico baseado e capacitor com dieletrico higroscopico
This work present the development, fabrication and caractization of a microelectronic sensor, based on a capacitor with hygroscopic dielectric. The hygroscopic dieletric was obtained through LPCVD using a vertical reactor. Images obtained by Atomic Force Microscope ? AFM allowed to optimize the morphology of the hygroscopic dieletric. A circuit converter bas
Publicado em: 2005
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10. SPR: Uma nova ferramenta para biossensores
This paper reviewed the development and theoretical aspects of surface plasmon ressonance (SPR) technique and discusses this powerful sensor technology in the development of biosensors, as well as for the investigation of biological interactions and clinical assays. The SPR has been proven to be a valuable tool to investigate dynamic processes, such as adsor
Química Nova. Publicado em: 2003-01
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11. Obtenção e caracterização de filmes finos e ultra-finos de oxido e oxinitreto de silicio em sistema "home-made" de plasma remoto
This work describes the formation and the characterization of thin and ultra-thin silicon oxide (SiO2) and oxynitride (SiOxNy) films formed by a home-made low temperature remote plasma system (RP). In this system, a 6O0W, 2.45GHz microwave generator, allows the formation of films by deposition (RPCVD) and oxidation (RPO) processes. The films were characteriz
Publicado em: 1999
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12. Obtenção de filmes finos isolantes de SiO2 e Si3N4 por deposição quimica a fase vapor auxiliada por plasma remoto
Dieletric films, are used in a large amount of applications in semicondutors devices. Several plasma enhanced deposition techniques have been studied in order to obtain insulating materiais with quality that can be employed in processes of manufacturing of devices. In this work, depositions of two different dieletric films are studied, with two different tec
Publicado em: 1996